Unit 2 Flashcards
What is the term used to describe the decrease in output of a pump as the system pressure increases?
Pump slippage
What may be used inside the tank/reservoir to prevent excessive sloshing of the hydraulic fluid?
Baffles
What is the ideal construction design of a tank/reservoir to improve heat dissipation?
Deep & narrow
What is required when the heat generated by the system is more than the system can dissipate?
Oil cooler
How are hydraulic pumps typically rated?
Volumetric output & pressure
What is required to be installed in the hydraulic system when a positive displacement pump is used?
Pressure relief valve
What valve will bypass all controller safety features?
Manual lowering valve
What is the purpose of the relief valve
Prevent excessive pressure
Why is a check valve used in a hydraulic elevator system?
Permit flow in one direction
What creates hydraulic system pressure?
Resistance to flow
What device is often installed in the line leading to the pressure gauge to stabilize readings and protect the gauge from oscillations?
Pressure gauge snubber
What type of pump is used in most hydraulic elevator systems ?
Screw
What can be used to prevent rough starts and ensure smooth operation in cold machine room environments?
Oil heaters
What device is used to control flow of fluid in a hydraulic elevator system?
Valves
What type of valve can be used as a shut off valve?
Ball valve
